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Discussion Starter #1 (Edited)
Hi all just pulled my original 2g carb off my 66 nova for a rebuild as it was leaking fuel over my manifold . noticed it had a couple of holes in the base plate that are drilled at an angle from above butterflys to outside above mounting hole. (see photo)
are these factory and what do they do? cant seem to see them on any photo. They look as if they are factory made dont like the idea of unfiltered air being sucked havent come across these on any other carb ive rebuilt any ideas appreciated?




 

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These holes are indeed factory / o.e.m.

They were noted in some GM / RPD manuals as "vapor release orifices".

If you want to, you can seal these by first running a 6-32 tap through the holes and then install a very short 1/8" long X 6-32 set screw with a bit of 271 LocTite on the threads.

A lot of the 2-Jet Rochesters did not have these holes.


BTW - I see too, that your base plate has the "Timed / Ported Vacuum Port" for the distributor...
the majority of the 2-Jet models were all constant / plenum vacuum for the distributor, and not timed / ported vacuum like yours.
 

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Dont make any sense?

I agree with JR Fuel. They are factory and you dont need them. And of course unfiltered air will be drawn in there. And many I think most 2GC Rochester carbs dont have those holes. I soppose you could tap them out larger and hook up nitrous or acohol injection?LOL Randall
 
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